1. Field of the Invention
This invention relates to electrical connectors, especially to high density printed circuit board connectors. It particularly relates to right angle connectors that are secured onto the printed circuit board by press fitting.
2. Brief Description of Prior Developments
High density, press fit printed circuit board connectors as illustrated in U.S. Pat. No. 5,044,994 have been commercialized. The right angle header connector illustrated in this patent employs a single piece construction in which the pin terminals are secured in a one piece molded plastic housing. The housing comprises a pin retention body and forwardly extending top and bottom walls that form a shroud enclosing two sides of the pin field. As industry requirements for increased signal speed and improved isolation from electromagnetic interference (EMI) have evolved, the desirability for providing electrical shielding for these headers has increased. This need for enhanced electrical performance has occurred in the context of continuous pressure to maintain or reduce the production costs for such connectors.
PCT Application U.S. 96/04670 shows one approach for improving electrical performance of a vertical, high density pin header in which the connector body is formed as a one piece metal housing. The pin terminals of the connector are secured in a molded plastic insulative holder having sleeves surrounding the base of the pins to insulate the pins from the connector body. In this connector, the terminal tails are straight and are not bent as required for a right angle header.
Another factor that influences the overall cost of using such connectors is the ease and reliability of mounting them. This requirement is made difficult by the necessity of assuring that the press fit tails of the terminals of 30, 40, or more terminals, usually on a 2 mm.times.2 mm pitch, must be located according to very tight true position tolerances, so that the tails are not mispositioned during board mounting. Tight true positions tolerances are particularly difficult to achieve when the terminals are formed of a relatively thick, stiff material and/or when the vertical tails of the terminals are relatively long. In order to achieve such positioning, tail positioning wafers as shown in the above-identified U.S. Pat. No. 5,044,994 have been utilized. In another approach as illustrated in U.S. Pat. No. 5,593,307, a separate press block with tail bending features has been proposed. However, the need for providing true position tail location at low manufacturing costs is not fully satisfied by these approaches, because they either add additional cost or do not provide sufficient tail location.